Charged particle therapy systems have proven applications in the treatment of cancerous cells. Conventional radiation therapy uses X-rays which pass through the target volume and deliver an undesirable exit dose to healthy tissue. A charged particle beam path can be terminated at a precise location, minimizing damage to healthy tissue surrounding the target volume.
Current methods of delivering charged particles in pencil beam scanning (PBS) mode require the target volume be treated in layers, with each layer corresponding to a different charged particle beam energy level. Inter-layer switching time, which includes changing the energy level of the charged particle beam, can vary between several microseconds to several seconds and leads extended treatment times. Thus, if the dose was to be delivered while the particle gantry or patient positioning device (PPS) rotates, the radiation dose cannot be delivered fast enough to all the layers at a given gantry or PPS angle.